One way is to try Michael Behe’s knockout test – systematically try knocking out every piece of a machine, and see if there are any parts that aren’t absolutely essential. If everything’s critical, the system clearly couldn’t appear by evolution, because there simply is no previous step. Either the whole thing appeared fully formed, or it wouldn’t have appeared at all. I have a different idea: push evolution fast enough that you can see it happen, and watch for it to hit a wall.

I laid out the details here, and now I want to find out if this experiment would be practical – I might need an impractically huge population of bacteria to make it work. The first thing I need to learn is all the types of mutations that happen to living things: